It is known to place an inclined panel at the back of a truck bed to reduce the air drag normally caused by the truck's upright tailgate. A lock can be provided on this type of device to create a secure storage compartment underneath the panel. The panel may be installed in the truck using a hinge, and placed flat on the truck bed when not in use.
Alternatively, the device can be designed to be removable. Use of this type of device can reduce wind resistance of the truck, therefore increasing fuel efficiency, and may also improve traction and handling, particularly at high speed, by providing a downward force on the back of the truck.
Prior art devices, however, present certain disadvantages when not in use. In particular, when the device is left on the bed of the truck, it may use up valuable cargo volume, leave uneven edges protruding into the bed space, and subject the device to the wear and tear of loading, unloading, and shifting of the cargo. Alternatively, prior art removable devices tend not to be easily stored, once they are removed from the truck bed.
These problems are important when a typical actual patterns of truck usage are considered. Indeed, truck operators often drive trucks empty during part of a trip and drive them loaded during another part of the same trip. For example, they may drive an empty truck to a remote location, and then pick up cargo. They may also bring cargo to a remote location and return with the truck empty. If the device interferes with the cargo, risks being broken, or otherwise reduces the utility of the truck, it will be used seldom, if ever. Such a user therefore will not benefit from the fuel savings that he or she might have had in traveling during a portion of a trip when the truck bed is empty, and will also not benefit from the improved handling, particularly at high speed, which such devices provide.